The hypothesis that growth in mammals is "saltatory" or pulsatile as opposed to continuous was suggested by a prominent research group (Science 259:801, 1992). However, the suggestion was based on a questionable statistical data analysis. We have analyzed new data, collected by collaborators in NICHD, which bear on this issue. In one study, careful measurements of bone growth in rabbits showed no evidence of pulsatile growth, while in another study of human infants, carefully replicated measurements of length over time did not show evidence of saltations. Only by carefully defining the statistical hypotheses could the saltatory model be refuted because measurement of daily growth rate is significantly confounded by measurement error. Statistical consultants with many investigators at NIH were undertaken in support of data analysis for ligand-receptor, kinetic modelling, dose- response experiments. Several investigators of neural network technologies were begun. In one, the network is trained to recognized components of a time-varying spectrum. In another, the network attempts to learn and generalize patterns of biological activity of several compounds.